Lead-Acid Battery System And Lead-Acid Battery Life Estimation Method

Abstract

Described are a lead-acid battery system and life estimation method capable of accurately estimating a remaining life of a lead-acid battery by calculating a capacity turnover (CT) value during operation in consideration of at least one of a lower limit state of charge (SOC) or a low SOC dwell time. A capacity turnover value calculation unit calculates the CT value using at least one of a lower-limit-SOC-based correction coefficient KLSOC calculated based on a lower limit SOC, which is an SOC having the smallest value when the lead-acid battery is charged and discharged once, respectively, or a low-SOC-dwell-time-based correction coefficient Kt_LSOC calculated based on a low SOC dwell time tLSOC, which is an elapsed time until the next discharge or charge starts when a discharge ends below a reference SOC.

What is claimed is: 
     
         1 . A lead-acid battery system configured to estimate a remaining life of a lead-acid battery by comparing a capacity turnover value from a beginning to an end of life with a capacity turnover value during operation, the lead-acid battery system comprising:
 a capacity turnover value calculation unit configured to calculate the capacity turnover value during operation,   wherein the capacity turnover value calculation unit calculates the capacity turnover value during operation by using at least one of a lower-limit-state-of-charge-based correction coefficient calculated based on a lower limit state of charge (SOC), the lower limit SOC calculated by a lower limit SOC calculation unit configured to calculate the lower limit SOC, which is an SOC having a smallest value when the lead-acid battery is charged and discharged once, respectively, or a low-SOC-dwell-time-based correction coefficient calculated based on a low SOC dwell time, which is an elapsed time until a next discharge or charge starts when a discharge ends below a reference SOC.   
     
     
         2 . The lead-acid battery system according to  claim 1 , wherein
 the lower limit SOC calculation unit calculates, as the lower limit SOC, an SOC after an end of a discharge of the lead-acid battery to be subjected to calculation of the capacity turnover value during operation, and   the capacity turnover value calculation unit calculates the lower-limit-state-of-charge-based correction coefficient based on the lower limit SOC calculated by the lower limit SOC calculation unit.   
     
     
         3 . The lead-acid battery system according to  claim 1 , wherein
 the lower limit SOC calculation unit calculates, as the lower limit SOC, an SOC at a start of a charge immediately before a discharge of the lead-acid battery to be subjected to calculation of the capacity turnover value during operation, and   the capacity turnover value calculation unit calculates the lower-limit-state-of-charge-based correction coefficient based on the lower limit SOC calculated by the lower limit SOC calculation unit.   
     
     
         4 . The lead-acid battery system according to  claim 1 , wherein the lead-acid battery is a bipolar lead-acid battery. 
     
     
         5 . A lead-acid battery life estimation method wherein a remaining life of a lead-acid battery is estimated by comparing a capacity turnover value from a beginning to an end of life and a capacity turnover value during operation, the lead-acid battery life estimation method comprising:
 a capacity turnover value calculation step of calculating the capacity turnover value during operation,   wherein in the capacity turnover value calculation step, the capacity turnover value during operation is calculated using at least one of a lower-limit-state-of-charge-based correction coefficient calculated based on a lower limit state of charge (SOC), the lower limit SOC calculated in a lower limit SOC calculation step of calculating the lower limit SOC, which is an SOC having a smallest value when the lead-acid battery is charged and discharged once, respectively, or a low-SOC-dwell-time-based correction coefficient calculated based on a low SOC dwell time, which is an elapsed time until a next discharge or charge starts when a discharge ends below a reference SOC.   
     
     
         6 . The lead-acid battery life estimation method according to  claim 5 , wherein
 in the lower limit SOC calculation step, an SOC after an end of a discharge of the lead-acid battery to be subjected to calculation of the capacity turnover value during operation is calculated as the lower limit SOC, and   in the capacity turnover value calculation step, the lower-limit-state-of-charge-based correction coefficient is calculated based on the lower limit SOC calculated in the lower limit SOC calculation step.   
     
     
         7 . The lead-acid battery life estimation method according to  claim 5 , wherein
 in the lower limit SOC calculation step, an SOC at a start of a charge immediately before a discharge of the lead-acid battery to be subjected to calculation of the capacity turnover value during operation is calculated as the lower limit SOC, and   in the capacity turnover value calculation step, the lower-limit-state-of-charge-based correction coefficient is calculated based on the lower limit SOC calculated in the lower limit SOC calculation step.   
     
     
         8 . The lead-acid battery life estimation method according to  claim 5 , wherein the lead-acid battery is a bipolar lead-acid battery. 
     
     
         9 . The lead-acid battery system according to  claim 2 , wherein the lead-acid battery is a bipolar lead-acid battery. 
     
     
         10 . The lead-acid battery system according to  claim 3 , wherein the lead-acid battery is a bipolar lead-acid battery. 
     
     
         11 . The lead-acid battery life estimation method according to  claim 6 , wherein the lead-acid battery is a bipolar lead-acid battery. 
     
     
         12 . The lead-acid battery life estimation method according to  claim 7 , wherein the lead-acid battery is a bipolar lead-acid battery.